With development of technologies, touch screens are more and more widely applied. Touch screens utilize a haptic feedback system to replace a mechanical button panel so as to provide a simple and convenient human-computer interaction mode. According to different working principles, touch screens include a capacitive type, a resistive type, an infrared type, a surface acoustic wave type and the like. The capacitive touch screen works by utilizing a current sensing phenomenon of a human body, supports multipoint touch and has advantages of wear resistance, long service life, low power consumption and the like, and thus is rapidly developed and has been widely applied to electronic products such as a mobile phone, a tablet personal computer, a notebook computer, a television, a display, a digital photo frame, a navigator and the like.